Safety appliance for elevators.



G. W. LATHROM; J. w. P-OWLES.

SAFETY-APPLIANCE FOR ELEVATORS.

APPLICATION FILED SEPT. B, 1911.

Pazented Afir. 23, 1912.

I nu e11, tors messes UNITED sTATEs PATENT oEEIoE.

GEORGE w. LATHROP AND JAMES WILIlIAM POWLES, or EAMsEY COUNTY,

' MINNESOTA.

SAFETY APPLIANCE FOR ELEVATORS.

Specification 01! Letters Patent. Patented Apr, 23, 1912 Application filed September 8, 1911.

Serial No. 648,256.

' pliances for Elevators, of which the follow ingis a specification.

Our invention relates to improvements In safety appliances for electrically driven elevators. Its object is to provide a device within quick and easy access of the elevator operator whereby the electric current may be cut off from the driving motors in case the elevator controlling mechanism fails to p te-i A 'furt-her object is to provide a device a"dapte d' to automatically cut ofl the current from the driving motors of an elevator, in case the controlling mechanism permits the car to travel beyond a predetermined point either at the top or bottom of the elevator shaft. V

A further object is to prevent or permit as desired, the closing of the switch in the circuit of the'driving motors after the car.

has been automatically stopped, at its limit of movement.

Our'appliance is adapted for use in connection. with the well known types of electric elevators in which the brakes are con-' trolled by the electric current of the motor circuit. In these elevators the brakes are inoperative when the circuit is connected to drive the car and are setto-stop the car by discontinuing the current With such elevators accidents have occurred by reason of defective or badly managed controllers which while continuing the current have failed to regulate the movement of the car. In such event, the brake is useless because its application is dependent upon a cessation of current. Our. purpose is to obviate the danger due to this cause by providing emergency means for throwing off the current.

In the drawings Figure 1 is a side elevation of our improved safety appliance,

in detail of the grip; Fig. 3 is a sectional .monly used with electric. elevators. switch 11 which may be of the knife blade to driving mechanism (not shown) comtype, is mounted at the top of the. elevator shaft and is arranged in the electric circuit of the driving motors. The endless cable 12 is suspended vertically in the elevator idle sheaves 13. and 14. The'cord 15 attached at one end to the handle of the switch 11, passes over the pulley 16 and is divided into two branches 17 and 18 which are re spectively connected with the cable 12 on Opposite sides of the sheave 13. It will thusbe seen that the movement of the cable 12 in either direction will cause a downward pull on one or the other of. the branches 17 and 18 of the cord 15 to open the switch 11.

\Ve have provided a grip designed to be attached to the car and adapted to move the Cable 12 when manipulated lav-the operator. This'gripcomprises the members 21 and 22 pivoted together, the member 22 being mounted on a bracket 23 carried by the car.

One end of the members form handles 24L shaft, extending over and. guided by the and 25 while openings 26 and 27 through which the cable 12 passes, are formed in the blades 29 and 30. "The stop pin '31 on the member 22 engages the member 21 and normally holds said members in position against the act-ion of the spring 32 which is fixed between the handles 24 and 25. (When in normal position the openings 26 and 27 register with one another and permit the grip to pass freely-Lover the cable 12. When pressure is applied tothe handles the blades 29 and 30 are forced apart thereby causing the opposed edges of the openings to pinch and hold the cable 12.

The bracket 23 may be rigidly attachedto' the car, but weprefer to arrange it as follows: The guide 33 slotted at 34 is fixed to the car and forms a mounting for the bracket 23 which is clamped thereon in any position desired by the manipulationof the sliding block 37.

The stops 38 and 39 are arranged on the cable 12 to impinge against the blades 29 and 30, when in normal position at predetermined points in the travel of the car,

cuitto stop the car, if permitted thus automatically breaking the motor cirsuch points.

In operation, when the car becomes unmanageable the driver grasps the handles 24 and 25 and causes the grip to hold and move the cable 12. This action may take place at any point in the travel of the car and regardless of the direction in which the car is passing will open the switch 11 thus stopping the motors and car. Damage to the switch 11 is prevented by the branches 17 and 18, which when in alinement limit the movement of the cable 12' and form a tie 7 between the opposite sides of said cable as it is operated by the grip.' The stop 38 at the top or the stop 39 at the bot-tom ofjthe elevator shaft is engaged by the grip if the car-passes the predetermined upper or lower point, and breaks the circuit.

What we claim as new and desire to protect 11y Letters Patent is: 1.

prising an electrically driven car, an endless cable supported in position adjacent to the car, a grip on the car having blades surrounding said cable and handles in the car, a switch in circuit with a source of electric current, and acord connecting said switch and cable, forming a stop for said cable'toprevent damage to said switch and adapted to open the switch upon the movement of said cable in' either direction.

2. A device of the class described, comprising an electrically driven car, an endless cable, guide pulleys for said cable, .a grip vertically adjustable in the car in operative connection with said'cablc, stops on the cable in the path of said grip, a switch in circuit with a source of electric current,

and connecting means between said switch and cable whereby said switch is opened by the movement of said cable in either direction.

3. A device-of the class described, comprising an electrically driven car, a movable endless cable supported in position adjacent to the car, a vertically adjustable grip in the car, stops on the cable in the path of said grip, a switch in circuit with a source of electric current and connecting means between said switch and cable whereby said switch may be opened by the movement of said cable.

4. A device of the class described, comprising an electrically driven car, an endless cable supported in position adjacent to the car, a grip on the car in operative'conto pass device of the class described, com-v nection with said cable, a switch in circuit with a source of electrlc current and connecting means between said swltch and cable structionot said switch and adapted to open forming a stop for said cable to prevent de- I the switch upon movement of the cable in either direction. I

5. A. device of theclass described, comprising an electrically driven car, an endless cable, guide pulleys. for said cable, a grip in the elevator car in operative connection with said cable, a switch incircuit with a source of electric current, and a cord attachedat one end to said switch for operating the same, and having'two branches at its other end, said branches being connected to oppo-' site sides of the cable whereby said cable is tied upon predetermined movement of said cable in either direction to prevent destruction of the switch.

6. A device of the class described, com- I prising an electrically driven car, an endless cable, guide pulleys for said cable, a grip on the car in operative connection with said cable, a switch in circuit with a source of electric current and a cord attached at one end to said switch and having branches at its other end connected to opposite sides of said cable whereby said switch is opened by the operation of the cable and said cable is tied by said branches to prevent destruction of the switch upon predetermined movement of the cable in either direction.

'7. A device of the class described, comwhereby the switch may be opened by-the movement of the cable in ither direction.

8. A device of the class described, comprising an electrically driven car, an endless cable, guide pulleys for said cable, a grip consisting of two arms having blades in operative connection with said cable and handles for moving said blades, a bracket for the grip, a guide on the car for said bracket, means for clamping the bracket on the guide, a switch in circuit with a source of electric current and connecting means between said switch and cable whereby said switch may be opened by the movement of said cable.

9. A device of the class described, com

prising an electrically driven car, an endblock and bracket, a nut" on the bolt for names to this specification in the presence of clamping said block and bracket to the guide, tWU 'subseribin g witnesses.

Stops on the cable in the path of said grip, a GEORGE RV LATHROP switch in circuit with a source of electric v 1 current and connecting means between said JAMES VILLIAM switch and cable whereby said switch may Witnesses:

be opened by the movement of said cable. J. E. STRYKER, In testimony whereof, we have signed our F. C. OASWELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

, Washington, I). 0. 

